Wireless :: How To Share 3g Connection Over Wifi / Lan Network

Below is how I have established network between my PC and my laptop at home (being novice in networking, it took me few days to achieve the feat). And it is working perfectly. I can easily share files between them.Laptop

IP Address: 192.168.1.4
Subnet mask: 255.255.255.0
Default Gateway: 192.168.1.2Desktop
IP Address: 192.168.1.5
Subnet mask: 255.255.255.0
Default Gateway: 192.168.1.2ASUS RT-N10+ Router,/b>
IP Address: 192.168.1.4
Default Gateway: 192.168.1.2

I have connected the Desktop PC to the router using a LAN cable, and laptop to router over WiFi. Both, PC and laptop are running on Windows 7 OS, are on same HomeGroup, have same username / password. Also, I have connected the Ethernet cable to LAN port 1 of the router.Click here to view a graphical representation of the network. Can't post image here, because I don't have 10 reputation points.Now, what I want is use connect to Internet using a 3G USB modem on one device and share it over the network on the other. I tried Huawei and Micromax 3G USB modem. Both obtain a new IP address whenever I connect to Internet (means they have dynamic IPs). Rest, both have Subnet Mask as 255.255.255.255 and Default Gateway as 0.0.0.0. In that case, I cannot directly share Internet from the modem. Preferred DNS is blank for now in both, laptop and PC.What I am planning to do is to connect to Internet on laptop using the 3G modem and share the Internet connection over laptop's Wi-Fi (as hotspot) using Connectify, which I have done already. That, I suppose, will broadcast a static IP to connect to.Now what I can't figure out is that what changes should I make to the network settings of the router and the PC so that PC connects to the Internet broadcast by Connectify?